Avalanche Advisory

Turnagain Area Avalanche Advisory

Friday, March 27th 2015 6:21 am by Heather Thamm

ARCHIVED ADVISORY - All advisories expire after 24 hours from the posting date/time.

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The Bottom Line

Today the avalanche danger is MODERATE both in the Alpine and at Treeline. Triggering a wind slab up to 2’ thick is possible on steep sustained slopes. If the sun comes out today 1-2' of newly fallen snow will be susceptible to rapid warming and could produce natural wet avalanches on Eastern and Southern slopes. It will be important to avoid large steep slopes and pay attention to surface conditions if the sun makes an appearance today.

Below treeline heavy wet snow conditions could make recovery out of a terrain trap difficult. Keep an eye out for steep gullies, open drainages and tree wells at this lower elevation band.

Show the Complete North American Avalanche Danger Scale

North American Public Avalanche Danger Scale

Avalanche danger is determined by the likelihood, size and distribution of avalanches.

Danger Level

Travel Advice

Likelihood of Avalanches

Avalanche Size and Distribution

5 Extreme

Avoid all avalanche terrain.

Natural and human- triggered avalanches certain.

Large to very large avalanches in many areas.

4 High

Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.

Natural avalanches likely; human- triggered avalanches very likely.

Large avalanches in many areas; or very large avalanches in specific areas.

The Friends of the Chugach Avalanche Center is anofficial Pick. Click. Give. organization. When you apply for your PFD please consider supporting your public avalanche center. Every little bit helps and allows us to provide the best possible service. Thank you to all of our donors past, present and future!

This new snow will likely gain strength quickly as it settles, but triggering a wind slab up to 2’ thick is possible on steep slopes. Surface conditions below this new snow are variable with a sun crust on Southern and Eastern aspects and pockets of weaker snow on Northern and Western slopes. Today it will be important to avoid large steep sustained slopes and give this new snow a chance to adjust to the variable bed surfaces below.

Moderate ridgetop winds yesterday were transporting snow in the Alpine. Photo taken at 3200' on the ridgeline above Common Bowl,Tincan

Small D1 point releases "sluffs" and a fresh storm slab on "CFR" on Tincan mid day during a brief window of good visibility.

Day-time temperatures yesterday were warm and rain/snow line moved from 800’ in the morning to 1700’ in the afternoon. This caused a period of rapid melting below this elevation. Today wet loose avalanches on steep terrain features will be an additional hazard below treeline. 8-10” of heavy wet snow could be challenging to move through and early season conditions like open drainages and tree wells exist at this lower elevation band. Avoid terrain traps - it could be difficult to dig yourself out if caught up side down.

Two photos taken yesterday of the same tree at 1600'.1st picture was taken at 11:30am and the second was taken at 4pm after rain/snow line moved to 1700'. Photo by John Fitzgerald.

Mountain Weather

Total precipitation for Turnagain Pass was near an inch of water, which was a mix of rain and snow depending on elevation. Rain/snow line was at 800’ yesterday morning, but quickly moved to 1700’ by the afternoon. Temperatures at sea level were in the mid 30’s F to low 40’s F, and upper 20’s F at ridgetops. Ridgetop winds averaged in the 20’s mph with gusts into the high 40’s mph from the NE.

Today rain and snow showers are expected and patches of sun are possible. Rain/snow line will likely be near 2000’ today and up to 3” could fall at higher elevations. Temperatures will remain warm; high 30’s F at sea level and mid 20's F along ridgetops. Ridgetop winds will be from the East, 10-20 mph.

A low pressure system South of the Alaska Peninsula will bring another burst of rain and snow to Southcentral Alaska over the weekend. This will continue to bring us warm moist air, rain near sea level and snow in the interior and in the Alpine. It is uncertain how much precip will fall. Winds will likely be moderate at times, 20-30 mph from the East along ridgetops.

*Seattle Ridge Wx Station is not producing accurate wind direction data at this time.

PRECIPITATION 24-hour data (6am - 6am)

Temp Avg (F)

Snow (in)

Water (in)

Snow Depth (in)

Center Ridge (1880')

34

5

0.4

60

Summit Lake (1400')

36

1

0.1

12

Alyeska Mid (1700')

34

1

0.89

32

RIDGETOP 24-hour data (6am - 6am)

Temp Avg (F)

Wind Dir

Wind Avg (mph)

Wind Gust (mph)

Sunburst (3812')

26

ENE

23

49

Seattle Ridge(2400')

28

*

19

41

This is a general backcountry avalanche advisory issued for Turnagain Arm with Turnagain Pass as the core advisory area (this advisory does not apply to highways, railroads, or operating ski areas).

Riding status is not associated with avalanche danger. An area will be open to motorized use in accordance to the Forest Management Plan when snow coverage is adequate to protect underlying vegetation. Backcountry hazards including avalanche hazard are always present regardless of the open status of motorized use areas.

(Updated: Dec 18, 2018 )

AREA

STATUS

WEATHER AND RIDING CONDITIONS

Glacier District

Johnson Pass:

Open

Please stay on trail to avoid resource damage through Forested areas.

Placer River:

Closed

Closed

Skookum Drainage:

Closed

Closed

Turnagain Pass:

Closed

Closed November 21 due to inadequate snow conditions. #hopeforsnow

Twentymile:

Closed

Closed

Seward District

Carter Lake:

Open

Lost Lake Trail:

Open

Please stay on trail to avoid resource damage through Forested areas.

Primrose Trail:

Open

Please stay on trail to avoid resource damage through Forested areas.

Resurrection Pass Trail:

Closed

Closed for the 2018/19 season. Next season will be open to motorized use.

The information in this advisory is from the U.S. Forest Service, which is solely responsible for its content. This advisory describes general avalanche conditions and local variations always occur.
This advisory provided by the Chugach National Forest, in partnership with Friends of the Chugach National Forest Avalanche Information Center.